1) According to your description, the direct infringer in the case is your relative. You should sue your relatives directly, and you can also sue the bank together.

2) How much responsibility the bank has to bear in this mainly depends on whether the bank's operations violate relevant regulations. (For example, if your relative pretends to be you and calls the bank phone number and changes the bound phone number, if the bank has fulfilled its reasonable audit obligations in the process, the bank will not be at fault)

3) Specific circumstances It is recommended that you consult a local law firm or legal aid.